12-09-2017, 12:39 PM
Due to this electrical failure, the winding of the motor is heated which leads to an insulation failure and therefore reduces the life of the motor. This fault is generated in the induction motor due to the variation in the parameters of the induction motor. When the three-phase induction motor runs continuously, it is necessary to protect the motor from these anticipated faults. Three-phase induction motor generally connected directly through the source, if the supply voltage has sinking and swelling due to failure the performance of the motor is affected and in some cases the winding is burned. When the phase sequence (RYB) is reversed due to an incorrect connection, then the motor starts to rotate in another direction, if the supply system has only one phase and the other phase is disconnected, then it is a single phase problem.
The three-phase induction motor generally suffers from undervoltage, overvoltage, overheating, single phase and phase inversion problems. When the three-phase supply of the induction motor with a voltage higher than nominal then the induction motor starts overheating. In our project a variable resistance is used when the supply voltage is lower than the rated voltage, then the voltage drop across the resistor is greater than that which protects the motor from this failure. When the supply voltage is less than the voltage drop across the resistor is less than the specified value and the motor does not start. When the power supply is only a phase, it is a single phase problem and the supply voltage fall into the nominal one and, again, the motor fails to start. In case of motor overheating an LM sensor is used which detects the winding temperature if it exceeds the specified limit, then once again the motor will not start. It is highly desirable for the 3-phase induction motor to operate freely from all these types of faults.
In the 3-phase induction motor over-voltage protection system, it protects the motor from over-voltage, the voltage being higher than the rated voltage. In the circuit diagram of overvoltage protection consists the comparator that compares two voltages one is source and another is to fall through the variable resistance. When the voltage drop across the variable resistor is greater than the specified value then the comparator generates signals.
The three-phase induction motor generally suffers from undervoltage, overvoltage, overheating, single phase and phase inversion problems. When the three-phase supply of the induction motor with a voltage higher than nominal then the induction motor starts overheating. In our project a variable resistance is used when the supply voltage is lower than the rated voltage, then the voltage drop across the resistor is greater than that which protects the motor from this failure. When the supply voltage is less than the voltage drop across the resistor is less than the specified value and the motor does not start. When the power supply is only a phase, it is a single phase problem and the supply voltage fall into the nominal one and, again, the motor fails to start. In case of motor overheating an LM sensor is used which detects the winding temperature if it exceeds the specified limit, then once again the motor will not start. It is highly desirable for the 3-phase induction motor to operate freely from all these types of faults.
In the 3-phase induction motor over-voltage protection system, it protects the motor from over-voltage, the voltage being higher than the rated voltage. In the circuit diagram of overvoltage protection consists the comparator that compares two voltages one is source and another is to fall through the variable resistance. When the voltage drop across the variable resistor is greater than the specified value then the comparator generates signals.